Haines Avalanche Center

Forecast Expired - 11/27/2021

Above 2,500ftConsiderable

1,500 to 2,500ftConsiderable

Below 1,500ftConsiderable

Degrees of Avalanche Danger

Avalanche Problems

Problem 1

Storm Snow:

Most areas received 12-20″ of new snow in the last 2 days, and 35″ – 44″ this week. NW winds should be increasing today, potentially creating fresh wind slabs. Winds were blowing out of the SE for most the week, so all aspects are likely to contain wind-affected storm snow. All this new snow rests on a very weak layer of fluff that fell about a week ago. Any avalanches today could easily be 1 meter deep.

Anywhere the winds have been moving the new snow around you will find fresh hollow wind slabs that will be sensitive and poorly bonded. Human Triggered avalanches are likely today in terrain steeper than 30 degrees. Safety can be found in dense trees, and low-angle slopes.

Be especially mindful of gullies, creeks, and any other terrain traps, even below treeline. Steep openings in the trees will be likely to slide.

Likelihood:

  • Almost Certain
  • Very Likely
  • Likely
  • Possible
  • Unlikely

Size:

  • Historic
  • Very Large
  • Large
  • Small

Trend

  • Increasing
  • Steady
  • Decreasing

Problem 2

Persistent Slab:

 

Confidence: Low-Moderate

Elevation: From 2,500ft to 4,000ft

The lower snowpack in all zones contains one or more rain crusts from mid October. Weak facetted snow has formed above and below the crust, and has been found to be quite sensitive to the weight of our new snow. Any steep, open pockets of snowpack will be ripe to avalanche on this layer, about 90cm or deeper. We expect this October rain crust will be a lasting problem as we go into winter so keep your guard up! This layer exists on all aspects, but observations are limited and uncertainty is high.

 

What is the best way to manage this risk? We can simply avoid alpine terrain that is about 30 degrees and steeper. Be aware that venturing on these steeper alpine slopes is relatively high risk currently. Persistent slabs require a wide safety buffer.

Another way to reduce your exposure to these deep weak layers would be to stick to areas of deeper snowpack (>1m deep). But be wary of hidden rocks that can act as trigger points, and thin areas around the margins of a slab.

 

Likelihood:

  • Almost Certain
  • Very Likely
  • Likely
  • Possible
  • Unlikely

Size:

  • Historic
  • Very Large
  • Large
  • Small

Trend

  • Increasing
  • Steady
  • Decreasing

Weather

October brought heavy snow in the alpine, followed by a few rain/sun crusts. November has brought regular heavy snowfalls, adding up to 70+ inches so far. Winds have alternated between NW and SE.

New snow this week has been around 44″ in the Lutak zone, and 35″ in the Transitional zone. Winds were mainly from the SE above treeline. We can expect another inch or two of snow this weekend, with another 12+” possible Monday-Tuesday. Winds should be moderate out of the NW.

 Snow Depth [in] Last 24-hr Snow/SWE [in] Last 3-days Snow/SWE [in]  Today’s Freezing Level [ft]  Today’s Winds Next 24-hr Snow/SWE
Mount Ripinsky @ treeline **   60″ *  4″ / 0.35*  20″ / 1.70*  0′  mod, NW  2″ / 0.15*
Flower Mountain @ treeline  50″  2″ / 0.20  11″ / 0.90  0′  mod, NW  1″ / 0.10*
Chilkat Pass @ 3,100ft  23″  2″ / 0.15  9″ / 0.80  0′  mod, NW  1″ / 0.15*

( *star means meteorological estimate )

** The Ripinsky weather station is currently down, we will try to get it working again soon

Additional Information

In November, onX Backcountry is donating $10 of every membership to support forecasting. By leveraging their Slope Angle and Avalanche Forecast layers you’ll have access to the tools that help  inform safer backcountry travel this year.


 

Practice like you play. Make sure all your rescue gear is fully functional and your beacon has NEW batteries. Make sure 1) everyone in the group has a functioning beacon, shovel and probe 2) knows how to use them and 3) has trained in companion rescue in the last year. Keep your skills fresh. If you head into the hills, watch out for red flag avalanche conditions, natural avalanches, whoomphing or collapsing, and shooting cracks.

 

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